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为研究不同短截程度对苹果修剪反应以及新梢叶片光合特性的影响,以5年生‘富士’(Malus Domestica Borkh cv.Fuji)苹果树为试材,在休眠期对一年生外围延长枝条进行不同程度的短截,观察枝条的修剪反应,测定新梢叶片的叶绿素含量及叶片形态特征、光合参数、叶绿素荧光参数。结果表明:1)随短截程度的加重,枝条萌芽率降低,成枝力增大,抽发长枝比率明显增加,叶绿素a含量增加;延长枝增长增粗,延长枝重量、节间数、春秋稍长度显著增加。2)净光合速率、蒸腾速率随短截程度加重明显增大,这可能是短截之后新梢叶片叶肉细胞本身光合能力增强导致。3)最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSⅡ)、光化学猝灭系数(qP)也随短截程度的加重而增大,电子传递更快,用于CO2同化的能量较多;相反,非光化学猝灭(NPQ)随短截程度加重而降低,用于热散失消耗的较少。
In order to study the effect of different short-cut degrees on the apple pruning reaction and the photosynthetic characteristics of shoots, the 5-year-old ’Malus Domestica Borkh cv. Fuji’ apple tree was used as test material, The stubs were observed. The chlorophyll content, leaf morphological characteristics, photosynthetic parameters and chlorophyll fluorescence parameters of shoots were determined. The results showed that: 1) With the increase of the degree of short-cut, the rate of budding decreased, the branching force increased, the proportion of long-branch growing significantly increased and the content of chlorophyll-a increased; the branch growth, A slight increase in spring and autumn length. 2) The net photosynthetic rate and transpiration rate increased obviously with the degree of short cut, which may be caused by the enhanced photosynthetic capacity of shoot tip mesophyll cells after short cut. 3) The maximum photochemical efficiency (Fv / Fm), the actual photochemical efficiency (ΦPSⅡ) and the photochemical quenching coefficient (qP) also increased with the degree of short cut, the electron transfer was faster and the energy used for CO2 assimilation was more. In contrast, non-photochemical quenching (NPQ) decreases with increasing degree of shortness and consumes less heat for dissipation.